BSCI 222 Lecture Notes - Lecture 9: Hfr Cell, Wild Type, Electroporation
2 Oct 2015
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Bsci 222 - lecture 9 - bacterial and viral genetic systems. Smaller circular molecules that contain additional genes ( mini-chromosome ) Prototroph - can grow on minimal media. Lederberg and tatum - genetic exchange in bacteria. Bacteria will take up naked dna from its environment. Crossover in the bacterium leads to recombinant chromosomes. Map distances can be determined by transformation. The frequency of cotransformation is inversely proportional to map distance. Most cells are not competent to take up dna from the environment. Cells must be carefully grown and chemically treated to induce competency. Electroporation is commonly used to increase efficiency of transformation of competent cells. Dna is moved from one cell to another via cytoplasmic bridge. Conjugation requires direct contact between the cells of the two strains. Difference is the presence of the f plasmid. The crossing over between the f factor and chromosome produces.
